Tests for corrosive and acid gas, pH and conductivity, and for the presence of halogens are specified in many standards for low smoke, halogen free (LSHF) and related cables.
Each cable standard specifies different combination of these tests.
Test Methods & Equipment
Test methods are specified in BS EN (IEC) 60754-1, BS EN (IEC) 60754-2, BS EN 50525-1.
The main test equipment is a high temperature tube furnace, in which small samples of insulation or sheathing material are pyrolysed at around 850C. Gases emitted are collected in wash bottles and the chemical content is then analysed by a number of techniques including titration, pH / conductivity electrodes, and ion chromatography. A small scale test for halogen content involves burning the material in the presence of sodium metal.